The purpose of this research is to examine the role of calcifiable proteolipid in biologic calcification. By applying techniques developed in the study of microbial calcification to vertebrate systems the proteolipid dependency of vertebrate calcification might be established. Although proteolipids are normal constituents of biologic membranes, not all tissues normally calcify. Therefore the following approach is proposed: Calcifiability of proteolipid from non-calcifying tissues with a potential for ectopic calcification, ectopic deposits and tissues not known to calcify will be examined. Should non-calcifiable proteolipids be detected they will be compared biochemically to calcifiable proteolipids. The interaction of proteolipid with other tissue components during mineralization will be evaluated by studies on progressive calcification of cartilage and experimental rickets. Antibody to Bacterionema matruchotii proteolipid will be used to identify structural homologies among calcifiable proteolipids and to localize the proteolipid within the membrane.